The radial truck of the type known as the DR-1 has been proven to reduce considerably the lateral force on the rail in curves and to greatly improve the stability of the lateral action in high speed tangent track operation, there is however, a further source of truck skew and wheel wear that should be eliminated and that is the truck rotating force developed by truck bolster anchored body mounted brake rigging. This rotative force is the result of a couple produced by the brake top rod pulling the upper end of the truck live lever which is located at a lateral distance from the truck center of rotation, the center plate, and reacts at the bolster via the dead lever fulcrum, also laterally displaced from the center of rotation.
A truck mounted brake assembly which utilizes dual push-rods through the bolster is so designed that all of the braking forces are reacted within the brake rigging and side frames so that no truck rotative forces are developed. However, this brake assembly requires the use of both of the brake rod holes through the truck bolster and since the DR-1 Radial Truck steering arms also require the use of one of the two holes, the two units are incompatible as currently designed.